Bolt-type container seals, or seal locks, have been used for many years to seal and lock cargo shipping containers. These seals were originally designed as a next-generation seal that followed earlier, and simpler, band-type seals. Seals indicate to the receiver of the container whether someone made unauthorized access to the container's contents. Bolt-type seals provide a higher level of security than a band seal because they are harder to break.
The construction of a typical bolt-type seal is very simple in that it primarily consists of a hardened steel bolt that is passed through latching or locking structure on a container door and then inserted into a locking member. The door locking structure is often nothing more than existing holes or slots in a shipping container door. The locking member part of the seal permanently engages with the bolt's end and therefore prevents retraction or removal of the bolt. The container is opened by using a bolt-cutter that destroys the bolt and, consequently, makes both the bolt and locking member unusable. For reference purposes, an example of this type of seal lock is illustrated in U.S. Pat. No. 3,945,671.
On the outside, the present invention looks similar to the type of seal lock described above. However, the present invention has design improvements that are intended to both save cost and improve the way shipping records are transported with containers.
First, it needs to be appreciated that large numbers of shipping containers are used on a world-wide basis. Major shippers like United Parcel Service (U.P.S.) currently purchase large quantities of bolt-type seals on an annual basis. While there may be some reusable bolt-type seals in use today, these seals are typically one-use only, as per the above description. The bolt is destroyed when it is cut and the locking mechanism is simply thrown away. For some shippers the annual cost attributable to seal lock purchases is significant because of the large numbers of containers that use seals of this kind. Therefore, the successful development of a bolt-type seal design that is reusable, or recyclable, presents an opportunity for significant cost savings.
Second, there is always supporting documentation that accompanies a container when it is shipped. This documentation generally includes manifest documents, shipping documents, and other kinds of documents relating to supply chain or tracking information. Anything that provides large shippers with a more efficient way of accessing or transmitting information of this kind is advantageous.
The invention disclosed here is designed to address both of the issues described above. The specific details and features of the invention are set forth below.